Aluminum diamond cutting tool

Abstract

A novel diamond cutting tool and its use in cutting and grinding applications. The cutting surface of the tool is composed of an aluminum/diamond metal matrix composite comprising diamond particles dispersed in a matrix of aluminum or an aluminum alloy, and wherein the diamond particles have thin layers of beta-SiC chemically bonded to the surfaces thereof.

What is claimed is: 
     
       1. A method for machining a workpiece comprising:
 fabricating a diamond cutting tool by a pressure infiltration of molten aluminum or an aluminum based alloy in a cylindrical compact of SiC-coated diamond particles surrounding an inner metal core, thus providing a cylindrical diamond cutting tool comprising an outer diamond-containing cutting surface bonded to the inner metal core, wherein said outer diamond-containing cutting surface is composed of an aluminum/diamond metal matrix composite comprising diamond particles dispersed in a matrix of aluminum or aluminum based alloy; 
 cutting or grinding said workpiece with the rotating diamond cutting tool; and 
 redressing the cutting tool by at least partially dissolving the matrix of aluminum or aluminum based alloy to expose additional diamond particles dispersed in said matrix. 
 
     
     
       2. The method of  claim 1 , wherein said aluminum/diamond metal matrix composite has a thermal conductivity of greater than about 500 W/mK. 
     
     
       3. The method of  claim 1 , wherein said outer diamond-containing cutting surface has a thickness of from about 0.020 inch to about 1.00 inch. 
     
     
       4. The method of  claim 1 , wherein the diamond particles have thin layers of beta-SiC chemically bonded to surfaces thereof, and the beta-SiC layers are comprised of a conversion coating formed by a chemical vapor reaction of SiO with the diamond particles. 
     
     
       5. The method of  claim 1 , wherein said matrix is an aluminum based alloy containing silicon as a second major component. 
     
     
       6. The method of  claim 1 , wherein a concentration of diamond particles in said aluminum/diamond metal matrix composite is within a range of from about 20 to about 80 volume percent. 
     
     
       7. The method of  claim 6 , wherein said diamond particles concentration is within a range of from about 55 to about 70 volume percent. 
     
     
       8. The method of  claim 1 , wherein said diamond particles are coarse diamond particles having an average particle size of about 150 micron. 
     
     
       9. The method of  claim 1 , wherein said diamond particles are fine diamond particles having an average particle size of about 15 micron. 
     
     
       10. The method of  claim 1 , wherein said inner metal core is formed of titanium, stainless steel, zirconium or molybdenum. 
     
     
       11. The method of  claim 1 , wherein said outer diamond-containing cutting surface and said inner metal core are each provided with interlocking grooves or protrusions for improved bonding between them. 
     
     
       12. The method of  claim 1 , wherein said diamond cutting tool also includes a cylindrical metal shank member secured at one end thereof to said inner metal core and coupled at its other end to an apparatus for rotating said tool. 
     
     
       13. The method of  claim 12 , wherein said shank member is formed as an integral unit with said inner metal core. 
     
     
       14. A diamond cutting tool comprising a cylindrical outer diamond-containing cutting surface formed by a pressure infiltration of molten aluminum or an aluminum based alloy in a cylindrical compact of SiC-coated diamond particles and bonded to an inner metal core, said outer diamond-containing cutting surface being composed of an aluminum/diamond metal matrix composite comprising diamond particles dispersed in a matrix of aluminum or an aluminum based alloy, wherein said outer diamond-containing cutting surface and said inner metal core are each provided with interlocking grooves or protrusions for improved bonding between them. 
     
     
       15. The diamond cutting tool of  claim 14 , wherein said aluminum/diamond metal matrix composite has a thermal conductivity of greater than about 500 W/mK. 
     
     
       16. The diamond cutting tool of  claim 14 , wherein said outer diamond-containing cutting surface has a thickness of from about 0.020 inch to about 1.00 inch. 
     
     
       17. The diamond cutting tool of  claim 14 , wherein the diamond particles have thin layers of beta-SiC chemically bonded to surfaces thereof, and the beta-SiC layers are comprised of a conversion coating formed by a chemical vapor reaction of SiO with the diamond particles. 
     
     
       18. The diamond cutting tool of  claim 14 , wherein said matrix is an aluminum based alloy containing silicon as a second major component. 
     
     
       19. The diamond cutting tool of  claim 14 , wherein a concentration of diamond particles in said aluminum/diamond metal matrix composite is within a range of from about 20 to about 80 volume percent. 
     
     
       20. The diamond cutting tool of  claim 19 , wherein said diamond particles concentration is within a range of from about 55 to about 70 volume percent. 
     
     
       21. The diamond cutting tool of  claim 14 , wherein said diamond particles are coarse diamond particles having an average particle size of about 150 micron. 
     
     
       22. The diamond cutting tool of  claim 14 , wherein said diamond particles are fine diamond particles having an average particle size of about 15 micron. 
     
     
       23. The diamond cutting tool of  claim 14 , wherein said inner metal core is formed of titanium, stainless steel, zirconium or molybdenum. 
     
     
       24. The diamond cutting tool of  claim 14 , further including a cylindrical metal shank member secured at one end thereof to said inner metal core. 
     
     
       25. The diamond cutting tool of  claim 24 , wherein said shank member is formed as an integral unit with said inner metal core. 
     
     
       26. A method for machining a workpiece comprising:
 fabricating a diamond cutting tool by a pressure infiltration of molten aluminum or an aluminum based alloy in a cylindrical compact of SiC-coated diamond particles surrounding an inner metal core, thus providing a cylindrical diamond cutting tool comprising an outer diamond-containing cutting surface bonded to the inner metal core, wherein said outer diamond-containing cutting surface is composed of an aluminum/diamond metal matrix composite comprising diamond particles dispersed in a matrix of aluminum or aluminum based alloy; and 
 cutting or grinding said workpiece with the rotating diamond cutting tool; 
 wherein said outer diamond-containing cutting surface and said inner metal core are each provided with interlocking grooves or protrusions for improved bonding between them. 
 
     
     
       27. The method of  claim 26 , wherein said matrix is an aluminum based alloy containing silicon as a second major component, and said inner metal core is formed of titanium, stainless steel, zirconium or molybdenum. 
     
     
       28. The method of  claim 26 , including redressing the cutting tool by at least partially dissolving the matrix of aluminum or aluminum based alloy to expose additional diamond particles dispersed in said matrix.